We see distant objects as they were at the time that light left them. Assuming a Hubble constant, H0, of 73 km/s/Mpc, what would be the age of the universe?

A) 13.7 million years B) ∞ (infinity) C) 13.7 billion years D) 47.4 billion years A) 13.7 million years B) ∞ (infinity) C) 13.7 billion years D) 47.4 billion years

Exam 25: Cosmology: The Origin and Evolution of the Universe

An object has a lookback time of 1 billion years. Assuming it is nonrelativistic, and that the Hubble constant is 22.4 km/s/Mly, what would be the measured value of its H_" $\alpha$ (656.3-nm) line?

(Multiple Choice)

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Question 41

At about what time after the Big Bang did the universe pass through the transition from a radiation-dominated to a matter-dominated universe?

(Multiple Choice)

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Question 42

It is not yet known whether we live in an unbounded universe that will expand forever or in a bounded universe that will eventually recollapse. How are astronomers trying to settle this question?

(Multiple Choice)

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Question 43

The cosmic background radiation is the:

(Multiple Choice)

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Question 44

Newton reached the conclusion that the universe must consist of an infinite expanse of stars because:

(Multiple Choice)

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Question 45

What was it that caused the apparent expansion of the universe?

(Multiple Choice)

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Question 46

From what direction do we receive the cosmic microwave background?

(Multiple Choice)

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Question 47

What is the z value for an object on our cosmic light horizon?

(Multiple Choice)

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Question 48

Einstein introduced a "cosmological constant" into his formulation of the structure of the universe on the basis of the general theory of relativity. How did he envision that this cosmological constant would manifest itself?

(Multiple Choice)

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Question 49

We see distant objects as they were at the time that light left them. Assuming a Hubble constant, H₀, of 73 km/s/Mpc, what would be the age of the universe?

(Multiple Choice)

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Question 50

For any object moving uniformly, velocity = distance/time. If so, in the Hubble relationship for the expansion of the universe, V = H₀d, what is the significance of the constant 1/H₀?

(Multiple Choice)

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Question 51

If the elliptical galaxy in Hydra, shown at the bottom of Figure 23-16 (Universe, 11th ed.), were to be at a distance of 3 billion ly, what would be a lower limit to the age of the universe? (Be careful with units.)

(Multiple Choice)

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Question 52

What major problem would arise if the value of the Hubble constant turned out to be 100 km/s/Mpc?

(Multiple Choice)

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Question 53

The farthest object we have seen (in 2011) has a redshift z of about 7.09, which corresponds to a recessional velocity v = 0.970c. What is the light travel time for this object as a percentage of the estimated age of the universe, 13.4 billion years?

(Multiple Choice)

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Question 54

I thought that the Big Bang was hot! If the cosmic microwave background radiation is the radiation left over from the Big Bang, why then is it only 3 K?

(Multiple Choice)

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Question 55

How does the measured mass density of matter in the universe, including the hypothesized dark matter, compare to the critical density required to just close the universe?

(Multiple Choice)

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Question 56

Compared to the average density of matter in the present universe, the equivalent "mass density" of radiation, using Einstein's relation E = mc² for the photons, is:

(Multiple Choice)

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Question 57

The expansion of the universe means that:

(Multiple Choice)

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Question 58

Suppose it is discovered that the Hubble constant is half the value we have been using. (The redshifts have all been measured correctly.) What would this mean for the calculated distances to distant galaxies?

(Multiple Choice)

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Question 59

Astronomers currently estimate the age of the universe to be:

(Multiple Choice)

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Question 60

Showing 41 - 60 of 68

Exam 25: Cosmology: The Origin and Evolution of the Universe

An object has a lookback time of 1 billion years. Assuming it is nonrelativistic, and that the Hubble constant is 22.4 km/s/Mly, what would be the measured value of its H" α\alphaα (656.3-nm) line?

At about what time after the Big Bang did the universe pass through the transition from a radiation-dominated to a matter-dominated universe?

It is not yet known whether we live in an unbounded universe that will expand forever or in a bounded universe that will eventually recollapse. How are astronomers trying to settle this question?

The cosmic background radiation is the:

Newton reached the conclusion that the universe must consist of an infinite expanse of stars because:

What was it that caused the apparent expansion of the universe?

From what direction do we receive the cosmic microwave background?

What is the z value for an object on our cosmic light horizon?

Einstein introduced a "cosmological constant" into his formulation of the structure of the universe on the basis of the general theory of relativity. How did he envision that this cosmological constant would manifest itself?

We see distant objects as they were at the time that light left them. Assuming a Hubble constant, H0, of 73 km/s/Mpc, what would be the age of the universe?

For any object moving uniformly, velocity = distance/time. If so, in the Hubble relationship for the expansion of the universe, V = H0d, what is the significance of the constant 1/H0?

If the elliptical galaxy in Hydra, shown at the bottom of Figure 23-16 (Universe, 11th ed.), were to be at a distance of 3 billion ly, what would be a lower limit to the age of the universe? (Be careful with units.)

What major problem would arise if the value of the Hubble constant turned out to be 100 km/s/Mpc?

The farthest object we have seen (in 2011) has a redshift z of about 7.09, which corresponds to a recessional velocity v = 0.970c. What is the light travel time for this object as a percentage of the estimated age of the universe, 13.4 billion years?

I thought that the Big Bang was hot! If the cosmic microwave background radiation is the radiation left over from the Big Bang, why then is it only 3 K?

How does the measured mass density of matter in the universe, including the hypothesized dark matter, compare to the critical density required to just close the universe?

Compared to the average density of matter in the present universe, the equivalent "mass density" of radiation, using Einstein's relation E = mc2 for the photons, is:

The expansion of the universe means that:

Suppose it is discovered that the Hubble constant is half the value we have been using. (The redshifts have all been measured correctly.) What would this mean for the calculated distances to distant galaxies?

Astronomers currently estimate the age of the universe to be:

Astronomy and the Universe

Knowing the Heavens

Eclipses and the Motion of the Moon

Gravitation and the Waltz of the Planets

The Nature of Light

Optics and Telescopes

Comparative Planetology I: Our Solar System

Comparative Planetology II: the Origin of Our Solar System

The Living Earth

Our Barren Moon

Mercury, Venus, and Mars: Terrestrial, yet Unique

Jupiter and Saturn: Lords of the Planets

Jupiter and Saturns Satellites of Fire and Ice

Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

Asteroids, Comets, and Impacts

Our Star, the Sun

The Nature of the Stars

The Birth of Stars

Stellar Evolution: on and After the Main Sequence

Stellar Evolution: The Death of Stars

Stellar Remnants: Neutron Stars and Black Holes

Our Galaxy

Galaxies

Quasars and Active Galaxies

Exploring the Early Universe

The Search for Extraterrestrial Life

Filters

An object has a lookback time of 1 billion years. Assuming it is nonrelativistic, and that the Hubble constant is 22.4 km/s/Mly, what would be the measured value of its H_" $\alpha$ (656.3-nm) line?

We see distant objects as they were at the time that light left them. Assuming a Hubble constant, H₀, of 73 km/s/Mpc, what would be the age of the universe?

For any object moving uniformly, velocity = distance/time. If so, in the Hubble relationship for the expansion of the universe, V = H₀d, what is the significance of the constant 1/H₀?

Compared to the average density of matter in the present universe, the equivalent "mass density" of radiation, using Einstein's relation E = mc² for the photons, is: